Design and simulation of an energy homeostaticity system for electric and thermal power management in a building with smart microgrid

Nowadays, microgrids are gaining importance in electric power generation and distribution environments due to their flexibility, versatility, scalability and the possibility of supplying ancillary services when connected to the grid. They allow for the customization of electric supply for very different types of consumers. Therefore, a new control model for power and energy management based on homeostaticity of electric power systems (EPS) is presented, which has been already analyzed and approved by ENEL Chile in its developmental stage. ENEL, the largest electric utility in the country, is interested in incorporating smart microgrids in the electricity distribution market, as part of a worldwide policy. Such microgrids are to be installed in buildings serviced by ENEL. To demonstrate the model’s utility, a Simulink model of a real microgrid is used, which is comprised of PV generation, energy storage, an air conditioning (AC) equipment and thermal storage of the building upon which the microgrid is installed. The behavior of every element is simulated, including the dynamic thermal model of the building in order to optimize energy management and power supply versus consumption. The behavior of the whole system is analyzed under different environmental profiles and energy consumption patterns using the proposed homeostaticity system.Ministry of Education RTI2018-094917-B-I00Fondo Nacional de Desarrollo Científico, Tecnológico y de Innovación Tecnológica FPU16-03522,3170399,FP

Stability Analysis: Two-Area Power System with Wind Power Integration

This paper focuses on a comprehensive stability study of a two-area power system with wind power integration and synthetic inertia control in each area, considering the effects of varying the interconnection link. Normally, synthetic inertia proposals are analyzed in one-area systems, in which stability is tested without considering transmission system phenomena, such as coherency. As modern power systems are progressively becoming interconnected, the possibility of forming two or more non-coherent areas is likely, which poses a challenge to synthetic inertia control techniques that use system frequency as a main feedback signal. In this context, this work addresses a crucial gap in the existing literature and provides a valuable starting point for studying more complex interconnected power systems with wind power integration. Simulations were performed in Matlab-Simulink considering a data-driven frequency dynamics model of the Chilean Electric System, and a wind power model with synthetic inertia control H2 norm minimization in each area. The results showed that it is possible to find local optimal feedback gains, preserving the stability of the global system under significant variations in the interconnection link. RoCoF and Nadir indicators are provided, highlighting the benefits of synthetic inertia control, particularly in low-inertia situations

Impact of Residential Photovoltaic Generation in Smart Grid Operation: Real Example

AbstractThis paper assesses the impact of residential photo-voltaic (PV) generation on the operation of a distribution smart grid in Chile. In particular, we focus on distribution losses and bus voltage regulation. This smart grid is composed of three hundred residential customers and belongs to the Central Inter-connected System (CIS) of Chile. A set of scenarios with different daily load profiles and generating levels are considered. The demand of each client is obtained by measuring the total demand at the distribution transformer and is disaggregating it using consumption profiles. The possibility of reactive power injection through the PV power converters is also considered. To estimate its maximum impact, the reactive power injection is calculated by minimizing network losses through optimal power flow. The location of the PV generation is a random variable with uniform distribution, and the expected losses and voltage profiles are determined using the Monte Carlo method. Three levels of PV generation are considered, 5%, 10% and 15% of the total distribution load. As was expected, the voltage in all the buses of the system increases when reactive power is injected by the power converters of the PV generation. In addition, losses compared to the case without PV generation, decrease by 44% in the most favorable scenario and 1% in the worst case. An estimation for the 40% of residential customers in Chile, considering only 5% penetration of PV generation, give as more than 170.000 MWh of savings in generation per year

A Cost-Effective Methodology for Sizing Solar PV Systems for Existing Irrigation Facilities in Chile

In the last five years, the Chilean Ministries of Agriculture and Energy developed a national strategy to incorporate renewable energies into various economic sectors. Since 2013, more than 1500 off-grid solar photovoltaic (PV) systems, with power ranging from 1 kW to 3 kW, were installed to drive existing irrigation systems in small and medium-sized farms for the exportation of fresh fruit. A net billing regulation was also implemented in 2014. This study shows a cost-effective methodology for the sizing of solar PV systems for existing irrigation facilities in Chile, in an effort to improve the competitiveness of the fresh-fruit industry. The same methodology may also be implemented in other Latin American countries. The article presents the analysis of four projects (two in the Atacama Region, and two in the Maule Region). The baseline situation of the four units was studied, as well as the energy-efficient actions that may be applied, in addition to the recommended characteristics of the selected PV system to drive the irrigation systems of small fresh-fruit farms. Off-grid and on-grid solar PV systems were analyzed, including some particularities of the Chilean regulations. The required water demand of the irrigation systems and their corresponding pressure heads were also determined. The electricity demand of the system was calculated, and the PV system was designed for an optimal irrigation system. Additionally, an economical assessment was made for two years. In the first year, the cost effectiveness of energy-efficient actions was evaluated for the irrigation system, and it was found that they had paybacks of approximately two years. In the second year, the implementation of a PV system in each demonstrative unit was evaluated. The on-grid solar PV system performed better than the off-grid system, with evaluated paybacks of approximately 12 years. Finally, some recommendations for a well-designed on-grid solar PV system were made on the basis of it lasting over 25 years, with an adequate operation and maintenance plan